Well, I said "better in many aspects", not overall better. For me, the camera is not that much important. It's good enough on Xiaomi, but obviously it's better on iPhone.
It's personal preferences, for me the aspects of long battery life and turning the device into disposable cattle, not a pet, are much more important. The display on Xiaomi is decent, and that plus fast responsive apps the display shows is all I need from a phone.